You could use Semaphore or CountDownLatch in java.util.concurrent. Or, if your threads pass data objects to one another, a blocking queue.
Or, probably, use HandlerThread(s) that would communicate using Handler messages... 10.02.2012 2:21 пользователь "John Goche" <[email protected]> написал: > Hi all, > > The problem I am having is that the thread I need to call join() on so as > to wait for completion may not even yet be started when I call join(). Is > it > legal in Java to call join() on a thread which is not running, but which > will > eventually be run by a third thread? > > Thanks, > > JG > > 2012/2/9 John Goche <[email protected]>: > > Basically sendRequest() invokes a thread which calls runOnUiThread with > > a new Runnable() which in turn also invokes a new Thread(). It is this > latter > > thread which I need to wait for to finish. I thought of using the join() > method > > to force thread completion prior to continuation at a specific spot but > I am > > somewhat new to thread programming and I am not entirely sure > > about how to set things up. Will give it another go... > > > > Thanks for your help, > > > > JG > > > > 2012/2/9 John Goche <[email protected]>: > >> Thanks Kostya! > >> > >> I have traced the code with the debugger and found that even though > >> notify() is being called from within a thread instantiated from > sendRequest() > >> (which is not the same thread as sendRequest()'s thread), the notify() > is > >> being called before the wait(). > >> > >> I am assuming that if I call notify() before wait() the notification > gets lost? > >> If this is not so, someone please let me know. > >> > >> The problem I am having is that sendRequest() launches a new thead s, > >> and I need to be sure thread s completes before the code proceeds past > >> what I have marked with wait(). > >> > >> Any ideas on how to solve this synchronization problem? > >> > >> Thanks, > >> > >> John Goche > >> > >> > >> 2012/2/9 Kostya Vasilyev <[email protected]>: > >>> Are you calling notify() from inside sendRequest()? > >>> > >>> > >>> If so, it's the same thread, and notify has nothing to do. > >>> > >>> http://developer.android.com/reference/java/lang/Object.html#notify() > >>> > >>> Causes a thread which is waiting on this object's monitor (by means of > >>> calling one of the wait() methods) to be woken up > >>> > >>> > >>> From looking at the code you posted, there is no thread waiting on the > lock > >>> because you only have one worker thread, and when it's calling notify > it's, > >>> well, calling notify and not waiting on a wait(). > >>> > >>> > >>> For debugging, set a breakpoint at lock.notify, and use the DDMS thread > >>> monitor or the debugger window to examine your threads. > >>> > >>> > >>> You might want to look at this package, which provides higher-level > >>> concurrency classes, and try to find one that fits what you're trying > to do: > >>> > >>> > http://developer.android.com/reference/java/util/concurrent/package-summary.html > >>> > >>> ( ThreadPoolExecutor? BlockingQueue? ) > >>> > >>> -- Kostya > >>> > >>> 10 февраля 2012 г. 0:41 пользователь John Goche < > [email protected]> > >>> написал: > >>>> > >>>> Dear Android developers, > >>>> > >>>> I am having the following issue in Android: > >>>> > >>>> In one class I am having: > >>>> > >>>> -------------------------------------------- > >>>> > >>>> final Object lock = new Object(); > >>>> > >>>> Thread thread; > >>>> > >>>> @Override > >>>> public void onCreate(Bundle savedInstanceState) { > >>>> > >>>> super.onCreate(savedInstanceState); > >>>> > >>>> thread = new Thread() { > >>>> > >>>> @Override > >>>> public void run() { > >>>> > >>>> sendRequest("foo"); > >>>> > >>>> synchronized(lock) { > >>>> > >>>> try { lock.wait(); } catch (InterruptedException e) { > >>>> e.printStackTrace(); } > >>>> > >>>> } > >>>> > >>>> System.out.println("GOT HERE!!!"); > >>>> > >>>> ------------------------ > >>>> > >>>> which causes the sendRequest() to do a bunch of stuff. When such stuff > >>>> finishes I call: > >>>> > >>>> System.out.println("Notifying thread..."); > >>>> synchronized(lock) { > >>>> lock.notify(); > >>>> } > >>>> System.out.println("Thread notified."); > >>>> > >>>> ------------------------- > >>>> > >>>> and this code executed until the "Thread notified." println() > >>>> statement. But then I do > >>>> not see the waiting thread resume from where I called wait(). Here is > the > >>>> output > >>>> from adb logcat: > >>>> > >>>> I/System.out( 2395): Thread notified. > >>>> W/ActivityManager( 60): Launch timeout has expired, giving up wake > lock! > >>>> > >>>> I do not see where I am going wrong. Any ideas why the code is not > >>>> working as expected? > >>>> > >>>> Thanks, > >>>> > >>>> John Goche > >>>> > >>>> -- > >>>> You received this message because you are subscribed to the Google > >>>> Groups "Android Developers" group. > >>>> To post to this group, send email to > [email protected] > >>>> To unsubscribe from this group, send email to > >>>> [email protected] > >>>> For more options, visit this group at > >>>> http://groups.google.com/group/android-developers?hl=en > >>> > >>> > >>> -- > >>> You received this message because you are subscribed to the Google > >>> Groups "Android Developers" group. > >>> To post to this group, send email to > [email protected] > >>> To unsubscribe from this group, send email to > >>> [email protected] > >>> For more options, visit this group at > >>> http://groups.google.com/group/android-developers?hl=en > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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